1. Technical Field
This invention relates in general to inspecting electrical components during manufacturing and in particular to the final inspection of shipping trays of head gimbal assemblies after they are manufactured.
2. Background Art
In manufacturing, it is not uncommon for quantities of subassemblies or other elements to be moved from one processing station to the next on a transport device. When the elements leave the sending station, they typically have been counted or somehow configured and are expected to arrive at the receiving station in the identical condition. When there is a discrepancy in an arriving shipment, the manufacturing sequence is usually interrupted and may be shut down.
For example, in the final inspection area of a head gimbal assembly manufacturing operation, an operator visually inspects the number of suspensions in each shipping tray before it passes to the packing station. The purpose of this visual inspection is to ensure that the information on the data collection or tracking system is accurate.
The inspector takes a tray from a stack and, using a hand held scanner, scans the bar code label that identifies the tray. After waiting for the tray mapping information to appear on the screen of his nearby data terminal, the inspector visually compares what the system says should be on the tray, against what is actually on the tray. This procedure is then repeated for each tray in the stack. If no inconsistencies are found between the system information and the actual, physical inspection, the complete stack is sent to the packing station. Although this manual procedure is workable, a faster and more accurate system is desirable.
Therefore, it is a feature of the present invention to provide an automated system for inspecting trays of head gimbal assemblies to verify assembly-generated values.
It is another feature of the present invention to provide this inspection at higher speeds that manual inspections while reducing inspection errors.
A tray mapper uses an optical sensing array to detect if a head gimbal assembly suspension is located in each of the available positions in a shipping tray. Each tray to be inspected is placed on the mapper and located in a scanning position. A pair of electromechanical switches send a signal to a microprocessor indicating that the next tray is ready to be processed.
A bar code reader mounted on the mapper reads a label on the tray to access information regarding the tray and its contents from a central database. After the tray label is read, an optical sensor located beneath each position on the tray detects the presence or absence of a part. The microprocessor reads the status of each of the sensors against the values associated with the tray label. This information is used by the operator""s data terminal software to decide if the tray should be accepted or rejected. The operator is informed of the proper action via a text message on his terminal. The operator then handles the tray accordingly.